1. Field of the Inventive Concepts
The inventive concepts disclosed and claimed herein relate generally to luminescence-based analyzers, and more particularly, but not by way of limitation, to a luminescence-based analyzer having a shutter and illuminator assembly allowing both illumination and detection from the same side of an assay sample vessel.
2. Brief Description of Related Art
Analytical instrumentation utilizing luminescence detection is heavily utilized in the pharmaceutical and medical industries. Analytical measurements are often performed using a beam of catalyzing radiation to interact with a specific sample-reagent combination. The resulting photon emission, often very weak, is then detected and measured with a sensitive detector, converted to an electrical signal, and further correlated to provide the actual analytical result.
For example, U.S. Pat. No. 5,709,994 discloses a highly sensitive method of assaying known as a Luminescent Oxygen Channeled Immunoassay (LOCI). The method uses a photosensitizer that generates singlet oxygen upon irradiation, and a chemiluminescent compound that is activated by the singlet oxygen. The photosensitizer and the chemiluminescent compound are irradiated with light of a certain wavelength, after which the resulting light emitted by the chemiluminescent compound is measured and correlated to provide the assay.
The instrumentation utilized for luminescence-based assays is often physically large due, in part, to the intricate and sensitive optics used. The analyses often involve exposure of the sample, such as one contained in a microfluidic card, to a high intensity light in order to activate, for example, LOCI sensibeads. The resulting photon emission, often very weak, is then detected and measured with a sensitive detector such as a photomultiplier tube, converted to an electrical signal, and further correlated to provide the actual analytical result. Existing analyzers illuminate a sample in a microfluidic card from one side of the card, and the detection system is on the opposite side of the card. To protect the sensitive detector, it is common to widely separate the detector from the high intensity light source and to provide path barriers and shutters between the two.
Size is not a major concern in large laboratories facilitating high-throughput screening; however, it would be useful to have a lighter, portable unit or handheld device capable of producing accurate luminescence-based analyses. One approach for smaller units to achieve the proper illumination intensity without harming the detector is to utilize multiple illumination sources focused away from the detection optical axis. However, use of multiple illumination sources requires multiple access points to the assay vessel.
In view of the foregoing, there is a need for a luminescence-based sample analyzer that provides both sample illumination activation and sensitive luminescence detection from a single sample access point, while still protecting the sensitive detector. It is to such a compact and energy-efficient design that the presently disclosed and claimed inventive concept(s) is directed.